The present device generally relates to a cooling system for an induction hob provided with improved efficiency and versatility. In particular, a cooling system is provided for various high frequency inverters of some cooking hobs and the induction coils thereof, which are contributors to heat generated within the appliance.
Solutions for cooling induction cooking systems have been based on heat sink blocks, which may be typically made of extruded aluminum and to which electronic heat generating devices are attached. By the extruded nature of such heat sinks, the fins define cooling channels along a direction substantially parallel to the extrusion direction. These fins are usually ventilated by means of centrifugal blowers.
Such solutions have the disadvantage of becoming inefficient when the extrusion length of the heat sink increases. In fact, as the air is flowing along the heat sink path it gets progressively hotter as it absorbs heat from the heat sink surface. As a result, at the terminal end portion of the extruded heat sink the air temperature is significantly hotter than the air at the outlet of the blower. This results in a much lower capability to extract heat per unit area from the heat sink surface.
Other solutions for cooling induction systems have been based on the use of an axial fan projecting airflow onto a metal surface orthogonal with respect to the axial direction. This arrangement, which is typically used in single coil systems, entailing just two or three silicon devices to be cooled, has the disadvantage to be physically large both in the flow direction and in the orthogonal-to-flow direction, resulting in geometries hardly adaptable to low-profile built-in cook-tops.
Further solutions have consisted of an air blower having a semi-volute, positioned around a propeller to make air to directly flow on power components that form obstacles to passage of air flow evacuated by the blower. This solution has the combined disadvantage of creating high air pressure drop of the airflow (due to the impinged flow caused by the flat surface directly facing the fan outlet) and a relatively small heat-exchange surface compared to a “long extruded” heat sink. In fact the small heat-exchange surface substantially corresponds to the fan mouth (outlet) area. Accordingly, further advances may be desired.